Type II Hypersensitivity Reactions

C5b

C3b, along with being an opsonin, leads to activation of ___________ which leads to the formation of the MAC

RBCs

Many type II hypersensitivity reactions involve which kind of cells?

Destruction of platelets leads to thrombocytopenia, mucosal bleeding, petechiae, ecchymoses

What are the clinical signs of ITP?

Spherocytes and agglutination

What are the hallmarks of IMHA?

1. Opsonization and phagocytosis 2. Complement mediated inflammation and destruction 3. Antibody mediated cellular dysfunction

What are the three mechanisms by which there can be subsequent cellular destruction or dysfunction once antibodies are produced?

Anti-antibody antibody

What is the reagent in Coomb's test?

Phagocytosis and destruction of cells by macrophages

What is the result of opsonization?

IgG and IgM

Which antibodies act as opsonins when bound to antigen?

IgG and IgM

Which antibodies are produced in type II hypersensitivity?

Type II Hypersensitivity

Antibody mediated hypersensitivity in which antibodies react with antigens on the cell surface or in the extracellular matrix

Endogenous

(Endogenous/Exogenous) antigens in which antibodies develop against normal cell surface antigens - they are antibodies against self antigens

Exogenous

(Endogenous/Exogenous) antigens in which initial exposure to chemical or microbial proteins leads to production of antibodies and continued exposure to those antigens leads to hypersensitivity

Intravascular

(Extravascular/intravascular) hemolysis has a mechanism of destruction that involves lysis of RBCs mediated by complement and the MAC

Extravascular

(Extravascular/intravascular) hemolysis has a mechanism of destruction that involves phagocytosis of RBCs by macrophages in the spleen and liver

C3a and C5a; C3b

Activation of complement leads to production of __________ and __________ which incite inflammation but also leads to the production of __________

Antibody mediated cellular dysfunction

An antibody will block a hormone or neurotransmitter function when it binds to the receptor; it can also stimulate hormone receptors causing hormone prduction

Extravascular

Autoimmune hemolytic anemia is almost always (extravascular/intravascular)

RBC hemolysis leads to anemia Pale mucus membranes, icterus, weakness, tachycardia, tachypnea

What are clinical signs of IMHA?

Myasthenia gravis

Disease in which an antibody against hormone/neurotransmitter receptor can block hormone/neurotransmitter function

Graves disease

Disease in which an antibody can stimulate hormone receptors causing hormone production

Secondary IMHA/ITP

Diseases in which antibodies are directed against foreign antigens that are absorbed to the cell surface; the cells are destroyed as a result of immune response against the foreign antigen on their surface

Primary IMHA/ITP

Diseases in which breakdown of self tolerance leads to antibody formation against normal cell surface antigens

C3b and C4b

IgG and IgM can stimulate the classical pathway of complement and generate what, which act as opsonins?

Classical

IgG and IgM lead to activation of complement via the ______________ pathway

Positive

In a Coomb's test, agglutination of RBCs is a (positive/negative) result

Immune mediated hemolytic anemia (IMHA)

Type II hypersensitivity disease in which blood group antigens cause the opsonization and phagocytosis of RBCs

Surface antibody immunoglobulin test

Test in which RBCs are incubated with an anti-antibody mix that are labeled with a fluorescent tag; the blood is then run through a flow cytometer with a laser beam that will excite the fluorescent tag and if the anti-antibodies bind to RBCs they light up as they pass through the laser

Immune mediated thrombocytopenia (ITP)

Type II hypersensitivity disease in which platelet membrane proteins cause opsoniation and phagocytosis of platelets

Coomb's test

This test detects the presence of antibodies and/or complement bound to RBCs

MAC

____________ inserts into the cell membrane and leads to cell lysis